IEEE C802.16m-09/1889
Project
IEEE 802.16 Broadband Wireless Access Working Group <http://ieee802.org/16>
Title
Proposed Changes to Drops during HO (15.2.5.10.7)
Date
Submitted
2009-08-28
Source(s)
Kelvin Chou, Yih-Shen Chen, I-Kang Fu and
Paul Cheng
Kelvin.Chou@mediatek.com
MediaTek Inc.
Re:
Letter Ballot #30 on the Draft Amendment (IEEE P802.16m/D1)
Abstract
This contribution proposes some clarification to the MCHO section
Purpose
Propose to be discussed and adopted by TGm for the 802.16m Amendment
Notice
Release
Patent
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Proposed Changes to Drops during HO (15.2.5.10.7)
Kelvin Chou, Yih-Shen Chen, I-Kang Fu and Paul Cheng
MediaTek Inc.
I. Proposed Text
{Apply the following text modification to P802.16m/D1, Section 15.2.5.10.7 at page 102, line 35 as follows:}
---------------------------------------------------------- Text Start --------------------------------------------------------------15.2.57.10.7 Drops during HO
A drop is defined as the situation where an AMS has stopped communication with its serving ABS (either in the
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IEEE C802.16m-09/1889
DL or in the UL) before the normal HO procedures with the serving ABS has been completed.
An AMS can detect a drop by its failure to demodulate the DL, or by exceeding the AAI_RNG-REQ retries
limit allowed for the periodic ranging mechanism. An ABS can detect a drop when the Number of retries limit
allowed on inviting ranging requests for the periodic ranging mechanism is exceeded.
When the AMS has detected a drop during network reentry with a target ABS, the AMS follows the procedures
defined below to recover its connection:
-
If HO_Reentry_Mode = 1 and Disconnect Time has not expired, the AMS sends AAI_HO-IND message
with HO Event Code = 0b11 to cancel HO. When AMS transmits and serving ABS receives AAI_HO-IND
message with HO Event Code = 0b11 within Disconnect Time, regardless of AMS attempt at HO, the AMS
and serving ABS shall continue normal communication. In case of HO Reentry_Interleaving Interval > 0,
the serving ABS cancels HO Reentry Iteration of the AMS.
-
If HO_Reentry_Mode = 1 and Disconnect Time has expired, or HO_Reentry_Mode = 0, the AMS follows
the procedures defined below to recover its connection:

If Resource Retain Time has not expired, the AMS sends AAI_HO-IND message with HO Event
Code = 0b11 (HO cancel). When AMS transmits and serving ABS receives AAI_HO-IND message
with HO Event Code = 0b11 within Resource Retain Time, regardless of AMS attempt at HO, the
AMS and serving ABS shall continue normal communication.

If Resource Retain Time has expired, the AMS attempts network reentry with its preferred target ABS
as through cell reselection, which includes performing network reentry at the serving ABS.
When the serving ABS has detected a drop, it shall react as if a AAI_HO-IND message has been received with
HO Event Code = 0b10 indicating AMS unable to stay connected to serving ABS until expiration of disconnect
time.
----------------------------------------------------------- Text End ---------------------------------------------------------------
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